scholarly journals Geotechnics as an unavoidable segment of earthquake engineering

2020 ◽  
Vol 72 (10) ◽  
pp. 923-936
Keyword(s):  
Earthquake Engineering ◽  
Seismic Activity ◽  
Active Faults ◽  
Comprehensive Approach ◽  
Design Standards ◽  
Liquefaction Potential ◽  
Geotechnical Investigations ◽  
Current Design ◽  
Hydrogeological Properties

A broader overview of the role of geotechnics in earthquake engineering is given, and a set of practical examples of the quantification of geotechnical seismic indicators for construction of individual buildings is provided. An overview of oncoming changes to the current design standards for evaluating the effect the soil has on buildings in earthquake conditions is also given. Considering the level of seismic activity in Croatia, the need for adopting a comprehensive approach to seismic microzoning is emphasized, which involves a whole array of indicators, from lithological, engineering geological, and hydrogeological properties, and position of active faults, to identification of unstable slopes and zones of pronounced liquefaction potential, for which extensive geophysical and geotechnical investigations are required.

The Role of Weld Processing on the Integrity Assessment of Bimetallic Girth Welds

2014 ◽  
Author(s):  
Gabriel Testa ◽  
Nicola Bonora ◽  
Antonio Carlucci ◽  
Andrew Ruggiero ◽  
Gianluca Iannitti
Keyword(s):  
Weld Joint ◽  
Equivalent Material ◽  
Design Standards ◽  
Design Assessment ◽  
Integrity Assessment ◽  
Current Design ◽  
Girth Welds ◽  
Weld Process Simulation ◽  
Joint Material

Current design standards and codes do not provide specific guidance how to perform engineering criticality assessment with bi-metallic girth weld in lined or clad pipe. Recently, Bonora et al. (Proc. ASME 2013 32nd OMAE conf.) proposed the equivalent material method (EMM) which allows one to still use current design assessment routes. The method consists in considering instead of three materials in the weld joint, a single “equivalent” material with a flow curve defined as the interpolated lower bound of the three weld joint material flow curves. In this work, the applicability of the EMM was verified considering the effect associated to weld residual stresses. To this purpose, two flaw geometry configurations have been investigated. Particular relevance was given to the multi-pass weld process simulation. Numerical results indicate that the EMM always provides reasonable results in terms of applied J with respect to those obtained considering the effective multimaterials configuration in the weld joint.

ON THE ROLE OF BIOMONITORING IN THE ASSESSMENT OF THE HEALTH OF THE POPULATION EXPOSED TO MERCURY

2017 ◽  
pp. 2-7
Author(s):  
L. V. Lukovnikova ◽  
G. I. Sidorin ◽  
L. A. Alikbaeva ◽  
A. V. Galochina
Keyword(s):  
High Risk ◽  
Biological Monitoring ◽  
Clinical Examination ◽  
Inorganic Compounds ◽  
Risk Groups ◽  
Comprehensive Approach ◽  
Chemical Monitoring ◽  
Environmental Objects

When examining the population exposed to organic and inorganic compounds of mercury, a comprehensive approach is proposed, including chemical monitoring of environmental objects, biological monitoring, clinical examination of persons exposed to mercury, identification of high-risk groups.

scholarly journals Impact of earthquake-triggered landslides on catchment sediment yield

2015 ◽  
Vol 367 ◽  
pp. 291-296
Author(s):  
M. Vanmaercke ◽  
F. Obreja ◽  
J. Poesen
Keyword(s):  
Sediment Yield ◽  
Seismic Activity ◽  
Fold Increase ◽  
Sediment Concentration ◽  
Spatial And Temporal Variation ◽  
Strongly Correlated ◽  
Before And After ◽  
Sediment Export

Abstract. This study explores the role of seismic activity in explaining spatial and temporal variation in sediment export from the Siret basin in Romania. Based on long-term (>30 years) sediment export measurements for 38 subcatchments, we found that spatial variation in sediment yield (SY) is strongly correlated to the degree of seismic activity and catchment lithology. Combined, these factors explain 80% of the variation in SY. To investigate the role of earthquake-triggered landslides in explaining these correlations, we studied the temporal variability in sediment concentrations before and after the 7.4 Mw earthquake of 1977 for ten subcatchments. Despite the fact that this earthquake triggered many landslides, only one subcatchment showed a clear (3-fold) increase in sediment concentration per unit discharge after the earthquake. This shows that, although prolonged seismic activity strongly controls average SY, individual earthquakes do not necessarily affect sediment export at short timescales.

scholarly journals Calculation features of wall panels with monolithic cement bond of layers in the stages of installation, transportation and maintenance

Vestnik MGSU ◽  
2019 ◽  
pp. 367-375 ◽  
Author(s):  
Elena A. Korol’ ◽  
Marina N. Berlinova
Keyword(s):  
Middle Layer ◽  
Structural Features ◽  
Design Parameters ◽  
Competitive Advantages ◽  
Design Standards ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Current Design ◽  
Infinite Variety ◽  
Construction Practice

Introduction. When building residential, public and administrative buildings of various spatial structural designs (monolithic, precast-monolithic, precast, etc.), it is common practice to design self-sustaining (non-structural) outer walls within a storey. Developing and using new design and fabrication solutions of multilayer industrial-made wall panels in modern construction practice makes actual the issue of improving methods of their calculation in different stages of maintenance and under various sorts and combinations of loads and effects. However, there is an infinite variety of possible loading levels in practice and, therefore, the same variety of design approaches would be required. This is obviously unacceptable for engineering calculations, hence it is necessary to provide a monolithic matrix bond of layers, both technologically and structurally, which can provide a generalized approach to the calculation of multilayer enclosing structures in accordance with current design standards. Materials and methods. The article describes structural features of a multilayer wall panel made of structural concrete with the middle layer of concrete with low thermal conductivity and monolithic bond of layers. These features have an influence on creation of a design model and a calculation procedure in the stages of transportation, installation and maintenance. Results. The article has examined the structures described above in the sense of design parameters that provide their competitive advantages in strength and maintenance as compared with conventional mass-built enclosures. Conclusions. The studies demonstrate that when combining loads of force and non-force character, stresses in the considered structure do not exceed allowable values in all the stages what proves the prospects of using the multilayer panels with monolithic bond of layers for erection of various-purpose frame-panel buildings.

scholarly journals Tectonic stress regime in the 2003–2004 and 2012–2015 earthquake swarms in the Ubaye Valley, French Alps

2018 ◽  
Vol 175 (6) ◽  
pp. 1997-2008 ◽  
Author(s):  
Lucia Fojtíková ◽  
Václav Vavryčuk
Keyword(s):  
Seismic Activity ◽  
Joint Inversion ◽  
Earthquake Swarm ◽  
Active Faults ◽  
Tectonic Stress ◽  
Geological Mapping ◽  
Earthquake Swarms ◽  
Stress Regime ◽  
French Alps ◽  
Principal Axes

Abstract We study two earthquake swarms that occurred in the Ubaye Valley, French Alps within the past decade: the 2003–2004 earthquake swarm with the strongest shock of magnitude ML = 2.7, and the 2012–2015 earthquake swarm with the strongest shock of magnitude ML = 4.8. The 2003–2004 seismic activity clustered along a 9-km-long rupture zone at depth between 3 and 8 km. The 2012–2015 activity occurred a few kilometres to the northwest from the previous one. We applied the iterative joint inversion for stress and fault orientations developed by Vavryčuk (2014) to focal mechanisms of 74 events of the 2003–2004 swarm and of 13 strongest events of the 2012–2015 swarm. The retrieved stress regime is consistent for both seismic activities. The σ 3 principal axis is nearly horizontal with azimuth of ~ 103°. The σ 1 and σ 2 principal axes are inclined and their stress magnitudes are similar. The active faults are optimally oriented for shear faulting with respect to tectonic stress and differ from major fault systems known from geological mapping in the region. The estimated low value of friction coefficient at the faults 0.2–0.3 supports an idea of seismic activity triggered or strongly affected by presence of fluids.

Intersection Design and Decision–Reaction Time for Older Drivers

1997 ◽  
Vol 1573 (1) ◽  
pp. 68-71 ◽  
Author(s):  
David W. Naylor ◽  
Johnny R. Graham
Keyword(s):  
Reaction Time ◽  
Reaction Times ◽  
Older Drivers ◽  
Design Standards ◽  
Older Driver ◽  
The Past ◽  
Sight Distance ◽  
Stop Sign ◽  
Current Design ◽  
Design Value

Trends in automobile and roadway use have changed drastically over the past several years. Changes in the trends include an increase in the percentage of licensed drivers, annual miles driven, and an increase in the number of older drivers. Of particular concern is the increase in the number of older drivers and the question of whether the current design standards adequately meet the needs of the older driver. In this study, the perception-reaction time variable used in calculating intersection sight distance at stop sign-controlled intersections was evaluated. The current design value for the perception–reaction time is 2.0 sec, which has been used since the 1940s when the driving population was much younger. A field experiment was performed to determine an appropriate value for today’s driving population. Subjects were covertly videotaped as they entered two rural and two urban stop sign-controlled interactions. Mean decision–reaction times were determined for an older and a younger group of subjects. The older group, consisting of 104 subjects, averaged 69.3 years of age and had a mean decision–reaction time of 1.32 sec. A group of 104 younger subjects, less than 30 years of age, had a mean decision–reaction time of 1.24 sec. The 85th percentile decision–reaction time for the older group was 1.86 sec and for the younger group, 1.66 sec. Both times were less than the current AASHTO design value of 2.0 sec.

The EU in the Central Mediterranean: Impact and Implications of the Comprehensive Approach

2018 ◽  
Vol 20 (2) ◽  
pp. 205-222 ◽  
Author(s):  
Sophie Dura
Keyword(s):  
Comprehensive Approach ◽  
Refugee Crisis ◽  
Crucial Importance ◽  
Joint Operation ◽  
Central Mediterranean ◽  
Military Operation ◽  
Migrant Smuggling ◽  
Defence Policy ◽  
The Eu

Abstract The implications of the comprehensive approach to the EU refugee crisis are becoming apparent in the current actions of different players in the central Mediterranean, where a Common Security and Defence Policy (CSDP) military operation is present alongside Frontex’s joint operation Triton. Both cooperate closely with Libyan border authorities and the European Migrant Smuggling Centre of Europol. But this not only poses humanitarian problems as to how the EU should cooperate on these matters with Libyan officials, it also leads to a confusing meddling of different EU actors from distinct policy areas in matters of crucial importance to the Union. Against this background, the article delineates the competences and powers of the different actors. Another issue is the role of the European Parliament in the situation: it has little influence in the CSDP but strong links to the agencies. In this context the article will discuss the influence of the cooperation on parliamentary accountability.

Serviceability Assessment of Composite Footbridge Under Human Walking and Running Loads

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Faraz Sadeghi ◽  
Ahmad Beng Hong Kueh
Keyword(s):  
Concrete Slab ◽  
Model Verification ◽  
Human Walking ◽  
Steel Beams ◽  
Vibration Source ◽  
Design Standards ◽  
Reinforced Concrete Slab ◽  
Codes Of Practice ◽  
Current Design ◽  
Vibration Responses

Footbridge responses under loads induced by human remain amongst the least explored matters, due to various uncertainties in determining the description of the imposed loadings. To address this gap, serviceability of an existing composite footbridge under human walking and running loadings is analyzed dynamically in this paper employing a finite element approach. The composite footbridge is made-up of a reinforced concrete slab simply supported at two ends on top of two T-section steel beams. To model the walking and running loads, a harmonic force function is applied as the vibration source at the center of the bridge. In the model verification, the computed natural frequency of footbridge exhibits a good agreement with that reported in literature. The vibration responses in terms of peak acceleration and displacement are computed, from which they are then compared with the current design standards for assessment. It is found that the maximum accelerations and displacements of composite footbridge in presence of excitations from one person walking and running satisfy the serviceability limitation recommended by the existing codes of practice. In conclusion, the studied footbridge offers sufficient human safety and comfort against vibration under investigated load prescription.

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